Air admittance vent diaphragm assembly

ABSTRACT

An air admittance vent diaphragm assembly is disclosed. The assembly comprises a base, an annular retainer ring, and an annular malleable washer. The base has an annular portion and a stem extending orthogonally from the center of the annular portion. The annular retainer ring includes a circumferential skirt engaged with an outer perimeter of the annular portion of the base, with the stem extending beyond the annular retainer ring. The annular malleable washer is disposed between the annular retainer ring and the annular portion of the base.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of the present invention is pressure equalization mechanismsfor plumbing, disposal, and waste systems.

2. Background

The plumbing, disposal, and waste system (PDWS) of most residential andcommercial buildings, such as those associated with sinks, bathtubs, andtoilets, require mechanisms to equalize pressure between the PDWS andthe ambient atmosphere when the pressure in the PDWS is less thanatmospheric pressure. Pressure equalization is necessary to maintain theliquid trap seal employed in the most common PDWS.

Traditionally, external ventilation stacks have been used to vent thePDWS to building exteriors, thereby allowing the pressure within a PDWSto constantly equalize to atmospheric pressure. More recently, airadmittance vents (AAV) have replaced ventilation stacks. AAVs allow airto enter the PDWS and restrict air from flowing out of the PDWS. Byrestricting flow (which may include air, gases, and liquid waste) out ofthe PDWS, an AAV may be placed most anywhere within a building whilestill preventing negative pressure, i.e., less than atmosphericpressure, to build up within the PDWS.

In order to achieve the desired functionality, an AAV requires a valvethat can be responsive to small drops in pressure (less than 1/100 PSI)below atmospheric pressure. The valve also needs to be able to create agood seal in response to small increases in pressure within PDWS beingregulated. Finally, the preferred AAV will have a wide range ofoperating temperatures and will be inert to chemicals that are commonlyfound in a PDWS, most especially methane gas and water vapor.

SUMMARY OF THE INVENTION

The present invention is directed toward an air admittance ventdiaphragm assembly. The diaphragm assembly chiefly comprises a base, anannular retainer ring, and an annular malleable washer. The base has anannular portion and a stem extending orthogonally from the center of theorthogonal portion. The annular retainer ring engages the annularportion of the base. The annular malleable washer is disposed betweenthe annular retainer ring and the annular portion of the base.

In a first separate aspect of the present invention, the annularretainer ring includes a circumferential skirt which engages the baseabout the outer perimeter of the annular portion. The circumferentialskirt may include a raised lip, and the outer perimeter of the annularportion may include a beveled edge to engage the raised lip of thecircumferential skirt.

In a second separate aspect of the present invention, the annularportion of the base includes a first circumferential ridge and the sideof the annular retainer ring facing the annular portion includes asecond circumferential ridge. Optionally, the first and secondcircumferential ridges have different radii.

In a third separate aspect of the present invention, the annular portionof the base includes a stepped surface. This stepped surface may includetwo or more steps. In the two step configuration, the outer step isdisposed nearer to the annular retainer ring than the inner step.

In a fourth separate aspect of the present invention, the stem has across-section that is substantially X-shaped.

In a fifth separate aspect of the present invention, any of theforegoing aspects may be employed in combination.

Accordingly, the present invention provides an improved air admittancevent diaphragm assembly. Other objects and advantages will appearhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference numerals refer to similarcomponents:

FIG. 1 is an exploded view of an air admittance vent diaphragm assembly;

FIG. 2 is a cross-sectional view of an annular retainer ring for thediaphragm assembly of FIG. 1;

FIG. 3 is a cross-sectional view of a base for the diaphragm assembly ofFIG. 1;

FIG. 4 is a lateral cross-sectional view of the base stem for thediaphragm assembly of FIG. 1;

FIG. 5 is a cross-sectional view of the air admittance vent diaphragmassembly of FIG. 1;

FIG. 6 is a cross-sectional view of an air admittance vent with thediaphragm assembly shown in the open position; and

FIG. 7 is a cross-sectional view of an air admittance vent with thediaphragm assembly shown in the closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning in detail to the drawings, FIG. 1 illustrates an exploded viewof an air admittance vent diaphragm assembly 10. The diaphragm assembly10 has three primary components: a base 12, an annular malleable washer14, and an annular retainer ring 16. The annular retainer ring 16 isplaced over the base with the annular washer disposed between the base12 and the annular retainer ring 16. The annular retainer ring 16 is ina snap-fitting engagement with the base 12. The stem 18 extends throughthe center of the annular washer 14 and the annular retainer ring 16.

The annular washer 14 provides the sealing surface for the diaphragmassembly 10 and is preferably constructed from a malleable neoprene orsilicon material. Other materials, however, may also be used. Inchoosing an appropriate material, flexibility and inertness to certainchemicals, particularly methane gas and water vapor, should beconsidered. Similarly, the base and the annular retainer ring areconstructed from materials chosen to be inert to such chemicals. Thebase is preferably made out of a hard shore ABS material and the annularretainer ring is preferably constructed from polyethylene, althoughother materials may also be used.

Referring to FIG. 2, the annular retainer ring 16 includes an annularportion 20 and a circumferential skirt 22. One end of thecircumferential skirt 22 includes a raised lip 24 which is employed tocreate the snap-fit with the base as described below. The side of theannular portion 20 facing the base, when the base and the annularretainer ring 16 are engaged, includes a circumferential notch 26 and acircumferential ridge 28. The circumferential notch 26 is positioned toreceive a complementary rim on the perimeter of the base. Thecircumferential ridge 28 is positioned to engage and apply pressure tothe annular washer 14 when the diaphragm assembly is assembled.

The base 12 of the diaphragm assembly, illustrated in FIG. 3, includesthe stem 18 extending orthogonally from the center of an annular portion30. The annular portion 30 includes a stepped surface 32 and a raisedcircumferential rim 34 around the stepped surface 32. The side wall 42of the base 12 generally defines the outer perimeter of the annularportion 30. This side wall 42 includes a beveled edge 44 which ispositioned to mutually engage the lip (24 in FIG. 2) of the annularretainer ring. The stepped surface 32 includes an inner step 36 and anouter step 38. A circumferential ridge 40 is disposed around the outerstep 38. This circumferential ridge 40 is positioned to engage and applypressure to the annular washer when the diaphragm assembly is assembled.

A lateral cross section of the stem 18 is illustrated in FIG. 4. Thestem 18 has a central core 50 and four legs 52 extending therefrom, witha pair of legs 52 lying along each orthogonal axis, thus providing thestem 18 with a cross section that is substantially X-shaped. The dottedline 54 circumscribed about the cross section of the stem illustratesthe overall circumference of the stem 18 and generally represents theair admittance vent opening into which the stem is inserted during useof the diaphragm assembly. The X-shaped form of the stem 18 providesadditional volume through which air may flow, thus providing increasedair flow through the vent opening when the diaphragm assembly is in use.Furthermore, the X-shaped cross section of the stem 18 allows theeffective circumference of the stem 18 to be maximized within the airadmittance vent opening to limit lateral movement of the diaphragmassembly and help create a consistent seal during use.

Referring to FIG. 5, which is a cross-sectional view of the fulldiaphragm assembly, the raised lip 24 on the circumferential skirt 22 isshown engaging the beveled edge 44 of the base 12. This configurationpermits the annular retainer ring 16 to have a snap fit with the base 12and disposes of the need for any glues or adhesives.

The annular washer 14 is engaged with and deformed by thecircumferential ridges 28, 40 of the annular retainer ring 16 and thebase 12, respectively. The annular washer 14 extends from approximatelythe circumferential rim 34 to near the stem 18. Note that in the figuresthe size of the two circumferential ridges 28, 40 is exaggerated forillustration purposes. As a result, actual deformation of the washer isnot illustrated in FIG. 5. In practice, each circumferential ridge isproportioned to achieve a seal as described above, such being largely amatter of design choice. The two circumferential ridges 28, 40preferably have different radii, the difference of which may be aslittle as 2/1,000 of an inch. The difference in the radii of the twocircumferential ridges 28, 40 is generally a matter of design choice,which may be informed by the materials used for and the overallthickness of the annular washer 14. The deformation of the washer by thecircumferential ridges 28, 40 provides an airtight seal between thethree components of the diaphragm assembly 10.

When assembled, the inner step 36 of the base 12 is further away fromthe annular retainer ring 16 than is the outer step 38. The space 46formed between the inner step 36 and the annular washer 14 permits thewasher to have a limited amount of movement toward the base 12. Thecentral opening 48 of the annular retainer ring 16 also permits thewasher 14 to have limited movement outward away from the base 12. Thus,the washer 14 is provided with limited, bi-directional movement in thelongitudinal direction.

Referring to FIGS. 6 & 7, a diaphragm assembly 10 is schematically shownas part of an air admittance vent 60. The air admittance vent includes acap 62 and a base 64. The base 64 connects to the PDWS (not shown) andincludes a channel 66 through which ambient air is allowed to enter thePDWS. The diaphragm assembly 10 rests on the base 64 with the stem 18 inthe air admittance vent opening 68.

In FIG. 6, the diaphragm assembly 10 is shown in the open position,while in FIG. 7 the diaphragm assembly 10 is shown in the closedposition. When in the open position, the diaphragm assembly 10 allowsambient air to enter through the channel 66 and into the PDWS. Thisoccurs when the pressure in the PDWS is less than the pressure in theambient atmosphere. The diaphragm assembly 10 is caused to be in theclosed position when the pressure in the PDWS is greater than theambient atmospheric pressure. Under such circumstances, the stem 18 isforced down into the air admittance vent opening 68, and the annularwasher (14 of FIG. 5) forms a seal with the rim of the air admittancevent opening 68, thus preventing gases and fluids in the PDWS fromescaping into the ambient atmosphere around the air admittance vent.

Thus, an air admittance vent diaphragm assembly is disclosed. While anembodiment of this invention has been shown and described, it will beapparent to those skilled in the art that many more modifications arepossible without departing from the inventive concepts herein. Theinvention, therefore, is not to be restricted except in the spirit ofthe following claims.

1. An air admittance vent diaphragm assembly comprising: a base havingan annular portion and a stem extending orthogonally from a center ofthe annular portion; an annular retainer ring having a circumferentialskirt, wherein the circumferential skirt engages the base about an outerperimeter of the annular portion and the stem extends beyond the annularretainer ring; and an annular malleable washer disposed between theannular retainer ring and the annular portion; wherein the annularportion includes a stepped surface; and wherein the stepped surfaceincludes an outer step and an inner step, the outer step being disposednearer to the annular retainer ring than the inner step.
 2. Thediaphragm assembly of claim 1, wherein the stem has a substantiallyX-shaped cross section.
 3. The diaphragm assembly of claim 1, whereinthe outer perimeter includes a beveled edge.
 4. The diaphragm assemblyof claim 3, wherein the circumferential skirt includes a lip and the lipengages the beveled edge.
 5. The diaphragm assembly of claim 1, whereinthe annular portion includes a first circumferential ridge and a side ofthe annular retainer ring facing the annular portion includes a secondcircumferential ridge.
 6. The diaphragm assembly of claim 5, wherein thefirst and second circumferential ridges have different radii.
 7. Thediaphragm assembly of claim 1, wherein the base and the annular retainerring, in combination, include means for the outer perimeter of theannular portion and the circumferential skirt of the annular retainerring to mutually engage.
 8. The diaphragm assembly of claim 1, whereinthe base includes means for providing the washer with space for limitedbi-directional longitudinal movement.
 9. The diaphragm assembly of claim1, wherein the base and the annular retainer ring, in combination,include means for providing an airtight seal between the base, theannular retainer ring, and the annular malleable washer.
 10. Thediaphragm assembly of claim 1, wherein the stem has a lateral crosssectional shape adapted to increase airflow through an air admittancevent opening while maximizing an effective circumference of the stemwithin the air admittance vent opening.
 11. The diaphragm assembly ofclaim 1, wherein the base includes means for providing the washer withspace for limited bi-directional longitudinal movement.
 12. Thediaphragm assembly of claim 1, wherein the stem has a lateral crosssectional shape adapted to increase airflow through an air admittancevent opening while maximizing an effective circumference of the stemwithin the air admittance vent opening.
 13. An air admittance ventdiaphragm assembly comprising: a base having an annular portion and astem extending orthogonally from a center of the annular portion, thestem having a substantially X-shaped cross section, wherein an outerperimeter of the annular portion includes a beveled edge; an annularretainer ring having a circumferential skirt, wherein thecircumferential skirt engages the base about an outer perimeter of theannular portion and the stem extends beyond the annular retainer ring;and an annular malleable washer disposed between the annular retainerring and the annular portion.
 14. An air admittance vent diaphragmassembly comprising: a base having an annular portion and a stemextending orthogonally from a center of the annular portion, the annularportion including a first circumferential ridge and having a steppedsurface; an annular retainer ring having a circumferential skirt,wherein the circumferential skirt engages the base about an outerperimeter of the annular portion and the stem extends beyond the annularretainer ring, and wherein a side of the annular retainer ring facingthe annular portion includes a second circumferential ridge; and anannular malleable washer disposed between the annular retainer ring andthe annular portion.
 15. The diaphragm assembly of claim 14, wherein thefirst and second circumferential ridges have different radii.
 16. Thediaphragm assembly of claim 14, wherein the stepped surface includes anouter step and an inner step, the outer step being disposed nearer tothe annular retainer ring than the inner step.
 17. An air admittancevent diaphragm assembly comprising: a base having an annular portion anda stem extending orthogonally from a center of the annular portion, thestem having a substantially X-shaped cross section, and the annularportion includes a first circumferential ridge and has a steppedsurface; an annular retainer ring having a circumferential skirt, thestem extending beyond the annular retainer ring, wherein a side of theannular retainer ring facing the annular portion includes a secondcircumferential ridge, the first and second circumferential ridgeshaving different radii, and wherein the stepped surface includes anouter step and an inner step, the outer step being disposed nearer tothe annular retainer ring than the inner step; and an annular malleablewasher disposed between the annular retainer ring and the annularportion.
 18. The diaphragm assembly of claim 17, wherein an outerperimeter of the annular portion includes a beveled edge; and whereinthe circumferential skirt comprises a lip, the lip engaging the bevelededge.
 19. An air admittance vent diaphragm assembly comprising: a basehaving an annular portion and a stem extending orthogonally from acenter of the annular portion; an annular retainer ring having acircumferential skirt engaged with an outer perimeter of the annularportion, the stem extending beyond the annular retainer ring, whereinthe base and the annular retainer ring, in combination, include meansfor the outer perimeter of the annular portion and the circumferentialskirt of the annular retainer ring to mutually engage; and an annularmalleable washer disposed between the annular retainer ring and theannular portion; wherein the base and the annular retainer ring, incombination, include means for providing an airtight seal between thebase, the annular retainer ring, and the annular malleable washer;wherein the annular portion includes a stepped surface; and wherein thestepped surface includes an outer step and an inner step, the outer stepbeing disposed nearer to the annular retainer ring than the inner step.20. An air admittance vent diaphragm assembly comprising: a base havingan annular portion and a stem extending orthogonally from a center ofthe annular portion, the stem having a lateral cross-sectional shapeadapted to increase airflow through an air admittance vent opening whilemaximizing an effective circumference of the stem within the airadmittance vent opening; an annular retainer ring having acircumferential skirt engaged with an outer perimeter of the annularportion, the stem extending beyond the annular retainer ring; and anannular malleable washer disposed between the annular retainer ring andthe annular portion; wherein the base includes means for providing thewasher with space for limited bi-directional longitudinal movement;wherein the annular portion includes a stepped surface; and wherein thestepped surface includes an outer step and an inner step, the outer stepbeing disposed nearer to the annular retainer ring than the inner step.